An electronic component mounting device (hereinafter referred to as a mounting device) configured to perform a work related to mount of electronic component (electronic component mount related work), such as a screen printing machine and an electronic component placement machine, includes one or more work lines provided on a base for conveying and positioning a board and for performing a necessary work to the board. By the work lines, screen printing of paste such as solder paste and conductive paste is performed on the board, and the electronic component is placed on the board printed with the paste. The work lines provided in the mounting device are provided in a single space defined by the base and a cover member. The cover member is provided with a door portion for allowing an operator of the mounting device to access an inside of the space (i.e., to access the work lines). When the plurality of work lines configured to perform the work related to mount of electronic component independently of one another are provided on the base, a door portion is provided for each of the work lines so as to allow an access to the corresponding work line.
When a check of the work line is needed during the operation of the mounting device, the operator performs the check work by opening the door portion for accessing the work line. From the view point of ensuring safety of the work by the operator, when the door portion is opened, the mounting device stops an operation of the work line accessible through the opened door portion by the operator (Patent Document 1). Therefore, in the related art mounting device including a plurality of work lines provided in a single space, operations of all of the work lines are stopped when one of the door portions is opened.